Recently, permanent makeup has been in the spotlight as a beauty art for the human body that expresses beautiful faces by forming eyebrow lines, strengthening eyelashes, and permanently changing the shape of lips (Montgomery and Parks 2001; Wetzel 2012; AlQuorain et al. 2017). The areas where permanent makeup is most commonly applied as cosmetic tattooing are eyebrows and eyelashes, injecting pigments into the lip line and the entire lip, rouge of cheeks, and beauty spots (Wetzel 2012).
The yellow ink, which is commonly used in eyebrow and eyelash treatment, acts as a neutralizing pigment that corrects the ink material so that it is close to the customer's skin color, prevents discoloration of the ink material after the treatment, and extends the maintenance period. The red pigment plays a role in making the lips look thicker and sharpening the lip line, making the lips attractive.
In this study, by observing the red wine-colored ink pigment of the red families with a scanning electron microscope, we found that the pigment particles were evenly dispersed or gathered to form a lump. We identified the cubic particles as titanium dioxide, with a diameter of about 110 to 200 ㎚. The rod shapes were iron oxide and were about 600 to 700 ㎚ long.
Most of the lumps were spherical or elliptical. The titanium dioxide was lumped together into lumps of a variety of sizes, from about 5.4 to 12 ㎛.
Titanium dioxide's agglomeration is why the particles can easily accumulate on the skin during permanent makeup procedures. The desired color tone can be obtained only when the ink solution on the tip of the sharp needle accumulates without being dispersed or lost on the application area of the skin. Titanium dioxide provides the most commonly used nanoparticles for industrial paints, paper, textiles, plastics, and cosmetics. It is a white pigment with low toxicity and has anti-corrosion characteristics and high photocatalytic activity (Kotil et al. 2017).
Yellow ink is used as a neutralizing pigment to harmonize with the client's skin color when performing permanent makeup on eyebrows and eyelashes.
Our observations in this study confirmed that rod-shaped iron oxide and cubic titanium dioxide were dispersed in a taupe yellow ink pigment, and that there were lumps of titanium dioxide between the iron oxide and titanium dioxide particles. Iron oxide particles were about 670 ㎚ long and had a uniform shape.
Iron oxide is classified into rod-shaped iron oxide red, iron oxide yellow, and cubic iron oxide black. Red iron oxide and yellow iron oxide are similar in size and shape, so they are not easily distinguished by scanning electron microscopy (Jeon and Chang 2010).
In this study, yellow iron oxide added to taupe yellow ink had the same shape and size. Iron oxide is a fine powder with cohesive force, forms a large surface area, and has a magnetic field; so it has a high surface energy (Zheng and Zhang 2003).
In this study, iron oxide exhibited agglomeration, which helps facilitate the deposition of pigment particles on the skin and minimize loss of particles during permanent cosmetic procedures.
In particular, we observed many lumps formed by the physical compression of titanium dioxide particles in the taupe yellow ink pigment. These agglomerated surfaces were very smooth. We assumed that such a compacted surface lump is an artifact produced when the titanium dioxide raw material is manufactured.
As described above, when a compressed lump of 15 ㎛ in the ink pigment is accumulated in the dermal surface layer, it becomes difficult to express skin tone, and skin disease may also be caused. The pigment component added to the ink is not soluble in water or organic solvents, and the sizes of the particles are very irregular. Other substances harmful to the human body should not be added.
Beauty tattoos were invented before the modern era and are not a trend that temporarily becomes fashionable and then disappears. Tattooing must be done by a professionally trained practitioner using advanced medically certified equipment and needle cartridges with skilled techniques (Goldstein 2007).
In particular, non-toxic inks and inks that can last a long time in various colors must be developed continuously. Ultimately, tattoos should be medically safe and have no side effects after the procedure. Tattoos should help the person get an artistically pleasing image and help the person who wears the tattoo live a beautiful life.
The elements detected in inorganic substances added to red wine-colored ink were titanium (Ti), aluminum (Al), sulfur (S), chlorine (Cl), and iron (Fe). The elements detected in the taupe yellow ink pigment were iron (Fe), titanium (Ti), sulfur (S), and aluminum (Al). Iron (Fe). Titanium (Ti), sulfur (S), and aluminum (Al) were commonly present in the two ink pigments used in this study.
Semi-permanent cosmetic ink is composed of insoluble pigments dispersed in water and additives, such as dispersants and preservatives, and contain some flavorings. The most important component in semi-permanent cosmetic ink is a colorant, which is an insoluble pigment. Most tattoo inks consist of carbon black, colorants such as titanium dioxide and iron oxide, and auxiliary substances (Laux et al. 2016).
The color development of certain shades is affected by the number of metals added to the ink and by the purity of these metals (Bocca et al. 2018). Our analysis by scanning electron microscope observation and energy dispersion spectroscopy confirmed that the main pigment particles in red wine-colored ink were titanium dioxide, and iron oxide was the main elemental component in taupe yellow ink pigment.